DM seminar Dr Divya SR neuro, AIIMS

2. Basics in Neuro ophthalmology
• Introduction
• Visual loss & field defects
• Diplopia
• Supra nuclear ocular motility disorder
• Case Vignette
• Painful Ophthalmoplegia & Clinical PEARLS
• MCQs

3. Neuro-ophthalmology
• Diseases of the eye and the related neurological
apparatus
• Afferent: Optic nerve, retina, chiasm, visual
pathways, cortex
• Efferent: Cranial nerve III,IV,VI, ocular muscles, brain
stem control centers

4. Vision loss
 Monocular – lesion usually affects retina or optic nerve
 Binocular – lesion localized to or beyond the optic chiasm
 Retinal involvement – generally a/w ophthalmoscopic
abnormalities
 Most optic neuropathies involve visual acuity
 Spared acuity raise suspicion of Pre-Retinal, Retinal or
Retrochiasmal disease
 Reduction in the saturation or brightness of colors may be an
early sign of optic nerve disease

5.  Look for RAPD in affected eye in unilateral cases
 Retina or Optic Nerve damage
 Swinging flashlight test

6. Visual field defects

7. Vein
Disc
Macula &
Fovea
Artery
Optic cup

8. Features Primary Secondary Consecutive
Disc Papery
white
Grey white Waxy pale
Margins Clear Blurred Normal
Cup Seen well Filled up Present
Lamina
cribrosa
Prominent Not seen Not seen
Vessels in &
around disc
Minimal Sheathing Attenuated
Peripheral
fundus
Normal Changes + Altered
Kestenbaum sign
Hemorrhage & exudates Pigmented/ degenerated
Features of optic atrophy

9. Anatomy and Physiology of ocular motility
BRAINSTEM NUCLEI
OCULOMOTOR TROCHLEAR ABDUCENCS
INTER CONNECTING NEURONS
EXTRA OCULAR MUSCLES

10. Extra ocular muscles
SR & IR
• Primary action - elevation/depression (abducted eye)
• Secondary action – torsion, SR - intorter & IR extorter
• Tertiary action – adduction
SO & IO
• Primary action - torsion, SO intorter & I0 extorter
• Secondary action – depression/elevation (adducted eye)
• Tertiary action – abduction
MR & LR
• Adduction & abduction

11. DIPLOPIA
It is when more than one image ( two ) of the object of regard
are seen simultaneously
1.Is the diplopia monocular or binocular?
J Neurol Neurosurg Psychiatry 2004;75(Suppl IV):iv24–iv31. doi: 10.1136/jnnp.2004.053413

12. DIPLOPIA
J Neurol Neurosurg Psychiatry 2004;75(Suppl IV):iv24–iv31. doi: 10.1136/jnnp.2004.053413

13. • Alignment of Images
──horizontal, vertical, or oblique
• Direction of gaze that increases the separation of images
• Onset and progression of the symptoms
• Exacerbating and relieving factors
• Associated symptoms
• Past medical history and family history
DIPLOPIA

14. EXAMINATION FOR DIPLOPIA
• Complete ophthalmological and orthoptic assessment─ for
monocular diplopia
• Identify cause of misalignment in binocular diplopia
• Identifying the paretic muscle(s)
Subjective Tests ─ Maddox rod and Red lense tests
Objective Tests ─ Corneal light reflex tests ,
Cover tests
Three “diplopia rules”
(1) Separation of images is greatest in the direction of action of the
weak muscle
(2) False image is the more peripheral
(3) False image comes from the paretic eye

15. MADDOX ROD ASSESSMENT

16. COVER TESTS
• Based on fixation ability
 Cover/uncover …detect manifest deviation,
Exo/eso/hyper/hypotropia
 Alternate cover ….detect total deviation ( manifest + latent)
 ….dissociation test
 …..demonstrate subtle hypertropia
• To measure angle of deviation….prism cover test
J Neurol (2014) 261 (Suppl 2):S542–S558

17. Parks three-step test
Identifying the paretic muscle in vertical diplopia
1) To determine which eye is hypertropic in the primary position
RE hypertropic, one of four muscles must be paretic;
right eye depressors (right SO & IR) or left eye elevators
(left IO & SR )
2) To determine whether the hypertropia increases in right or
left horizontal gaze,
Worse on left gaze: Rt SO or left SR
3) To determine whether the hypertropia is worse on head tilting
to left or right (Bielschowsky test)
Worse on head tilt to right….> Rt SO
J Neurol Neurosurg Psychiatry 2004;75(Suppl IV):iv24–iv31. doi: 10.1136/jnnp.2004.053413

18. Hess Chart•Pictorial and reproducible record of eye movements
•Each eye is plotted in turn for the central fixation spot and targets
at 15 and 30 degree eccentricity, respectively
• The smaller field belongs to the paretic eye
•Neurogenic paresis will show the largest under action in
the direction of paretic muscle and the largest over-action
is seen in the contralateral synergist
•Mechanical defects show a compressed field without
obvious over-action.

19. Supranuclear Oculomotor Disorders
EYE MOVEMENTS
UNIOCULAR
DUCTION
BINOCULAR
CONJUGATE
DYSCONJUGATE
VERSION
VERGENCE
CONVERGENCE & DIVERGENCESACCADE, PURSUIT, VOR, OKN

20. FUNCTIONAL CLASSIFICATION
FUNCTIONAL
CLASSIFICATION
JERKY
BRINGS TARGET TO
FOVEA
WHEN TARGET IS
IN MOTION
WHEN HEAD IS IN
MOTION
TRACKING TARGET
IN VERTICAL&
HORIZONTAL
TO &FRO MOTION
IN AP AXIS
BRIEF HEAD
MOTION
SUSTAINED
HEAD MOTION
G
A
Z
E
S
H
I
F
T
I
N
G
GA
ZE
HOL
DIN
G
SACCA
DE
PURS
UIT
VERGE
NCE
VOR
OKN

21. saccade
“Saquer” – french – to pull
Rapidly programmed eye movement, bring target into fovea
• Latency-interval b/n appearance of target & onset of saccade- 200
msec
• Amplitude & Velocity- Directly proportional to each other
100-700 msec
• Accuracy-amount of undershoot/overshoot of target
Types of saccades
VOLUNTARY INVOLUNTARY
• Visually guided Reflexive
• Predictive Spontaneous
• Memory guided Fast phase of nystagmus
• Anti saccades

22. Saccade- mechanical properties
• Combination of 2 mechanical elements-
-pulse & step
• Pulse- (velocity command)- high frequency burst of neural
activity - powerful phasic contraction of EOM - overcomes
resistance of orbital tissue & inertia of globe
• Step- (position command)-sustained contraction arising from a
constant level of neural activity- keeps eye in the new position
• Integration of velocity coded into position code by neural
integrators : NPH & MVN, INC

23. • Premotor burst neurons: EBN : excite pulse mechanism before
saccade
• IBN: Inhibit pulse in antagonist muscles & help in moving with
contacting muscles
• Omnipause neurons: Inhibit all burst neurons, check
unwanted firing
EBN IBN Neural
integrators
Omni pause
Horizontal PPRF Medullary
Reticular
formation
NPH & MVN Nucleus Raphe
Interpositus
Vertical Ri MLF Medullary
Reticular
formation
INC Nucleus Raphe
Interpositus

24. SACCADIC PATHWAY
DeJong's The Neurologic Examination

25. Abnormal saccades
• Saccadic dysmetria: Cerebellar lesions
• Anti saccades: Frontal lobe/connection to basal ganglia
• Saccadic intrusions- interfere with macular fixation
- square wave jerks – spontaneous small amplitude paired saccades
with inter saccadic latency 150-200ms …..PSP, MSA, cerebellar
disease
-macro square wave jerks – larger amplitude(10-40) & shorter
latency(80ms)….MS, OPCA
-ocular flutter- to & fro horizontal saccades without inter saccadic
interval… MS, cerebellar disease
-Opsoclonus(saccado mania)- conjugate involuntary large amplitude
multidirectional saccades..brainstem / cerebellar disease/
paraneoplastic

26. Smooth pursuit
• Slow conjugate eye movement
• To track relatively slow moving targets
(no faster than 30° per sec)
• Voluntary or involuntary
• To keep image of a moving object at fovea
• Mediated by parieto-occipito-temporal-mesencephalic pathway
• Ipsilateral control
• Latency > 125m sec
• Can track target moving up to 30˚ – 40˚/sec or 2Hz

27. Retinal image
movement
Lateral
geniculate
nucleus
Striate
cortex
MT, MST,
posterior
parietal
cortex
First descussation of horizontal
pursuit pathway
Second descussation of horizontal
pursuit pathway
Fastigial nucleus, medial
vestibular nucleus
Cerebellar
cortex
Smooth
pursuit
movements
Pontine
nuclei
Ocular motor
nuclei (3,4, and 6)
FEF, SEF
Nucleus of optic tract pathway
Pathway for horizontal smooth pursuit

28. Retinal image
movement
Lateral
geniculate
nucleus
Striate
cortex
MT, MST,
posterior
parietal
cortex
First descussation of horizontal
pursuit pathway
Second descussation of horizontal
pursuit pathway
Y group neurons
Dentate
Nucleus
cerebellum
Vertical
Smooth
pursuit
movements
Nucleus
reticularis
Tegmenti
pontis
Ocular motor
nuclei (3,4, and 6)
FEF, SEF
Nucleus of optic tract pathway
Ipsilateral
cortical control
Pathway for vertical smooth pursuit

29. Lesions –smooth pursuit
• Frontal lesions – impair I/L pursuit
• Parietal lesions – decrease amplitude & velocity of I/L pursuit
• B/L occipital – abolish smooth pursuit
• MLF – vertical pursuit
• Upward pursuit – decussate in posterior commissure
• Downward pursuit – INC –
• Role of Cerebellum –
*dorsal vermis & fastigial nucleus …onset of pursuit
*paraflocculus & flocculus …sustain pursuit response

30. VOR
• Conjugate eye movement, moves eye equal & opposite to head
movement
• Velocity of 800 degree/sec within a brief reaction time of 15ms
• Two types: horizontal, vertical & torsional VOR
• Function: Fix retinal images during head movements
• VOR cancellation: Normal component: inactivates VOR when target
moving in same direction of head
• Semi circular canal for angular rotation
• The Otolith organ for linear acceleration

31. • Reflex starts by movement of head> stimulation of
vestibular sensors> VOR circuitry in brain stem> eye
velocity command
• Head rotation to right> stimulation of ipsilateral
HC>activation of right MR & left LR> eye rotates to
left
• Down ward head acceleration> stimulates both AC
• Upward head acceleration> both PC

32. Optokinetic reflex
• OKN : reflexive oscillation of eyes alternating slow &
quick phases, produced by movement of visual field
• Stabilizes eye during tracking of large moving visual
scene
• Responsible for sense of illusionary motion while
sitting in a vehicle
• Pathway : Retina>AOT> CTT>Inferior
olive>cerebellum(which receive vestibular fibres)

33. Nuclear Inter nuclear Lesions
• Abducens nuclear level: Lateral gaze palsy while looking to
ipsilateral direction, VOR also affected
• PPRF: Ipsilateral horizontal saccadic palsy, VOR not affected
• MLF: Inter nuclear ophtalmoplegia
• PPRF+ MLF= One& half syndrome, VOR spared
• Abducens complex+ MLF= One & half syndrome , VOR affected
• PPRF+MLF+facial nerve nuclei: 8&1/2 syndrome
• PPRF+MLF+b/l facial nerve nuclei: 15&1/2 syndrome

34. Inter nuclear ophthalmoplegia
• Due to a lesion of MLF in either pons or midbrain
• Continuity b/w abducens and contra lateral oculomotor nuclei via
MLF lost
• Type 1 INO: Lesion in midbrain near convergence area, on
conjugate gaze medial rectii are affected both sides
Normal abduction, convergence also affected
• Type II INO: Lesion midway b/w 3rd & 6th nerve nuclei
Adduction is affected on both sides with normal abduction
Convergence spared

35. If INO is bilateral
• abduction saccades also may be slow
• Upward beating and torsional nystagmus
• Type III INO: Lesion is in relay to 6th CN nuclei
Abduction is affected in both eyes with relatively
preserved adducion

36. Skew Deviation
• Common supra nuclear gaze palsy, of vertical type
• Interruptions in the pathway between VN & vertical oculo
motor CN nucleus
• When a person tilts head, eye in downward direction
moves oppositely
• If brainstem lesions below the level of decussation> eye on
side of lesion will be lower eye
• If lesion above level of decussation> eye on side of lesion
will be at higher level

37. • Ocular tilt reaction: Pathological head tilt,
inappropriate torsional rotation & skew deviation
• Head & superior poles of both eye rotate toward lower
eye
• The higher eye is incyclotorted
• Skew deviation may occur in combination with INO

38. Dorsal Mid brain syndrome
• Lesions involving posterior commissure fibers projected from INC
• Occurs in dorsal midbrain region, pineal gland lesions and hydrocephalus
• Components:
1. Impaired vertical gaze
2. Square wave jerks
3. Vergence dysfunction
4. Skew deviation
5. Convergence retraction nystagmus
6. Lid retraction
7. Light near pupil dissociation

39. CASE VIGNETTE
• 75 year old male
• C/o decreased sensation over right face along with right sided
ptosis X 15 days
• Loss of vision in right eye X 12 days
• O/E Right sided ptosis & complete ophthalmoplegia
• Absence of light perception & pupillary reaction right side
• Decreased pain perception along right V1&V2
Clinical possibility ???

40. Painful Ophthalmoplegia
• Orbital pain + any combination of I/L ocular motor
palsies, oculo sympathetic paralysis or sensory
distribution in V1&V2 distribution
• Localization: orbit/orbital apex/superior orbital
fissure/cavernous sinus/subarachnoid
space/mesencephalon

41. SITES STRUCTURES INVOLVED
MESENCEPHALON 3RD OR 4TH NERVE
SUBARACHNOID SPACE 3RD, 4TH OR 6TH IN VARYING COMBINATIONS
PARASELLAR REGION 2ND, 3RD, 4TH & 5TH NERVE IN VARYING
COMBINATION
POSTERIOR CAVERNOUS SINUS 3RD, 4TH , 6TH AND ALL DIVISIONS OF 5TH
NERVE
MIDDLE CAVERNOUS SINUS 3RD, 4TH, 6TH AND 1&2 DIVISIONS OF 5TH
NERVE
ANTERIOR CAVERNOUS SINUS 3RD , 4TH, 6TH AND FIRST DIVISION OF 5TH
HORNERS SYNDROME ACCOMPANY
CAVERNOUS SINUS PATHOLOGY AT ANY
SITE

42. SITES LOCALIZATION
ORBITAL FISSURE 3RD, 4TH, 6TH & FIRST DIVISION OF 5TH NERVE
IN VARYING COMBINATION
ORBIT 2ND , 3RD, 4TH, 6TH AND 1ST DIVISION OF 5TH
UNKNOWN ANY OCULAR MOTOR NERVE ALONE OR IN
COMBINATION
DIABETES, MIGRAINE, VASCULITIS

43. Clinical Pearls
• Nuclear lesions of 3rd nerve result in b/l ptosis
• Nuclear lesion of 3rd nerve often result in
weakness of superior recti b/l
• Fascicular 3rd nerve palsy in brainstem associated
with contra lateral long tract signs
• Isolated 3rd nerve palsy : Most likeley lesion
within subarachnoid space,
compressive/ischemic
•The compressive lesions most often affect pupillomotor fibres
• Exception: Lesion which press 3rd nerve from below
•Combination of oculomotor paresis and sympathetic denervation
almost pathagnomonic of cavernous sinus lesion
•Maxillary division of 5th nerve escapes damage at superior orbital
fissure
•Isolated involvement of either superior or inferior division of 3rd
nerve strongly suggest orbital lesion….. BUT
•4th CN palsy : Vertical diplopia, head tilt to normal side
•Combination of 6th & 12th in Nasopharyngeal Ca & Clival tumor